Strongly Correlated Fermi Liquid of ^3He Adsorbed in One Dimensional Meso-Pores

我们从量子简并和一维系统两个方面研究了~3He在一维介孔中的吸附状态。我们采用FSM-16型和TW1型作为多孔材料。FSM-16的孔径为18安，长度为5,000至10,000安，TW1的孔径为20安。当~3He粒子吸附在孔壁上时，圆方向的第一激发能估计大于100mK。这一估计表明，在100mK以下，圆方向的量子态落在基态。因此，可以预料到一维费米液体。我们测量了~3He在介孔中的吸附热容。热容等温线在一个原子层附近的覆盖率处显示出一个扭结。覆盖度越高，热容增量越大；覆盖度越高，热容增量越大。当温度低于100mK时，覆盖层以下的热容随温度的降低而增大。然而，在覆盖范围以上，热容…更多随着温度的升高而减少。结果表明，^3He吸附原子的第一层为固体，其余为液态。为了详细研究液态，我们测量了^3He在^4He预涂覆的介孔上的吸附热容，最低可达5mK。液层的热容与60mK以下的温度成正比。吸附在介孔中的~3He体系被认为是伪一维或完全一维的。在准一维情况下，温度依赖关系表示费米液体，并暗示在低温下存在自旋密度波的可能性。然而，在5mK以上的温度范围内，没有观察到自旋密度波。在完全一维的情况下，温度依赖关系表明Tomonaga-Luttinger液体。总之，~3He吸附在介孔中是量子简并态。热容的结果表明是一维系统，尽管我们没有直接获得证据。较少

We have studied the state of ^3He adsorbed in one dimensional mesopores regarding the quantum degeneracy and the one dimensional system. We used FSM-16 type and TW1 type as porous materials. Pore size is 18 A in diameter and 5,000 to 10,000 A in length for FSM-16 and 20 A in diameter for TW1. When ^3He particles are adsorbed on the wall of the pores, the first excited energy in the circular direction is estimated to be larger than 100 mK. This estimation indicates that the quantum state in the circular direction falls in the ground state below 100 mK. Therefore one can expect the one dimensional Fermi liquid.We measured the heat capacity of ^3He adsorbed in the mesopores. The heat capacity isotherm shows a kink at a coverage near one atomic layer. The increase in the heat capacity with coverage is larger above the coverage than that below the coverage. The heat capacity below the coverage increases with decreasing temperature below 100 mK. Above the coverage, however, the heat capacity … More decreases with temperature. The results indicate that the first atomic layer of ^3He adatoms is solid and the rests are liquid.To investigate the liquid state in detail we measured the heat capacity of ^3He adsorbed on ^4He-precoated mesopores down to 5 mK. The heat capacity of the liquid layers is proportional to temperature below 60 mK. The system of ^3He adsorbed in the mesopores is considered to be pseudo or perfect one dimensional. In the case of pseudo one dimension the temperature dependence indicates the Fermi liquid and suggests the possibility of the spin density wave at low temperatures. In our temperature range above 5 mK, however, the spin density wave was not observed. In the case of the perfect one dimension the temperature dependence indicates the Tomonaga Luttinger liquid.In summary the state of ^3He adsorbed in the mesopores is the quantum degeneracy. The results of the heat capacity suggests the one dimensional system, although we did not obtain the evidence directly. Less